1. Field of the Invention
The invention relates to a technology that generates and displays an image in a vehicle.
2. Description of the Background Art
Conventionally, an image generating apparatus captures images of a vicinity of a vehicle (hereinafter referred to as “host vehicle” that is driven by a driver, a main user of the vehicle), using a plurality of cameras mounted on the host vehicle, and then generates an image of the vicinity of the host vehicle (hereinafter referred to as “vicinity image”) viewed from a virtual viewpoint, based on the captured images. Then, a combined image is generated by superimposing an image of the host vehicle (hereinafter referred to as “host vehicle image”) on the vicinity image and the generated combined image is displayed on a display. However, in the generated vicinity image, if an object is existing behind the host vehicle viewed from the virtual viewpoint, an image of the object (hereinafter referred to as “object image”) in the combined image is overlapped and hidden behind the host vehicle image. Therefore, there are cases where it is difficult for the user to see the object existing behind the host vehicle viewed from the virtual viewpoint.
On the other hand, there is a technology where an image generating apparatus generates a combined image by superimposing, on a vicinity image, a host vehicle image having a high transparency rate (e.g. 50% or more) or a host vehicle image in a frame style that shows a body frame of the host vehicle by lines. In other words, there is a technology where the image generating apparatus generates the combined image in which the object image is not hidden behind the host vehicle image, and thus the user can see the object existing behind the host vehicle viewed from a virtual viewpoint in the combined image.
However, even if the user can see the object existing behind the host vehicle in the combined image due to the combined image generated by superimposing on the vicinity image the host vehicle image having a high transparency rate or the host vehicle image in the frame style, there are cases where it is difficult to correctly understand an actual distance between the host vehicle and the object. Concretely, when the image generating apparatus generates the combined image by superimposing the host vehicle image having a high transparency rate on the vicinity image, there are cases where the host vehicle image is unclear. As a result, the user cannot fully see the distance between the host vehicle and the object in the image, and thus cannot correctly understand the actual distance between the host vehicle and the object.
Moreover, when the image generating apparatus generates the combined image by superimposing on the vicinity image the host vehicle image in the frame style, the lines are shown in same thickness and a same color for all the body frame of the host vehicle. When the object image is overlapped with the host vehicle image in the combined image, since a portion of the object image is hidden behind the lines of the body frame showing the host vehicle image, depending on thickness of the lines, there are cases where it is difficult for the user to fully see the distance between the host vehicle image and the object image in the combined image.
Furthermore, the same color is used for all the lines to show the body frame. Therefore, the user cannot quickly distinguish a portion of the body frame of the host vehicle image that a particular line represents. As a result, there are cases where it is difficult for the user to correctly understand the actual distance between the host vehicle and the object.